Mechanics: MCQ Test (50 questions)

Question 1 of 50

When an object is immersed, either fully or partially, in a liquid, its weight appears to decrease, and this apparent decrease in weight is equal to the weight of the liquid displaced by the object. This principle is:

ABernoulli's principle
BArchimedes' principle
CPascal's principle
DHooke's law

Question 2 of 50

It is easier to roll a wooden cylindrical barrel than to drag it because-

AWhen it is pulled, the weight of the object acts
BThe force of friction in the rolling state is much less than the force of friction in the sliding state.
CThe barrel has a larger surface area in contact with the road when towing.
DAny option other than the above

Question 3 of 50

A boy suddenly sits down on a rotating round table. What effect will this have on the table's angular velocity?

Awill decrease
Bwill increase
Cwill remain the same
DNothing can be said

Question 4 of 50

What is the approximate height of an orbiting satellite from the Earth's surface?

A36,000km
B42,000km
C30,000km
DNone of these

Question 5 of 50

When the pendulum is taken to the moon, its time period is-

Awill remain the same
Bwill decrease
Cwill become zero
Dwill increase

Question 6 of 50

What is the reason for the absence of atmosphere on the Moon?

AIt is near the Earth
BIt receives light from the sun.
CIt revolves around the Earth
DThe escape velocity of gas molecules on it is less than their root mean square velocity.

Question 7 of 50

What is the unit of measurement of magnetic field?

ATesla
BAmpere
CCoulomb
DOm

Question 8 of 50

Which one of the following statements is not correct?

AThe weight of any body is different on different planets.
BThe mass of any body is the same on Earth, on the Moon and in the empty sky.
CThe state of weightlessness of any body occurs when it is balanced against the gravitational force acting on it.
DThe weight and mass of any body at sea level on the surface of the Earth are the same.

Question 9 of 50

A person pushes a wall but fails to displace it, then he does-

ANo work whatsoever
Bnegative work
Cpositive but not maximum work
DMaximum work

Question 10 of 50

The SI unit of temperature among the following is—

ARéaumur scale
BKelvin
CAmpere
DCandla

Question 11 of 50

Bernoulli's principle states the conservation of which of the following?

AMass
Benergy
CLinear momentum
Dpressure

Question 12 of 50

When a ship moving in a river reaches the sea, the level of the ship-

Aas much as before
Bwill come up a little
Cwill come down a little
Dwill move up or down depending on the load it carries

Question 13 of 50

The SI unit of energy is-

AJoule
BNewton
CHertz
DPascal

Question 14 of 50

If a body is thrown from the earth with a velocity of 11.2 km/s, then the body-

Awill never return to Earth
Bwill return in 2 hours
Cwill return after 24 hours
DNothing is certain

Question 15 of 50

A girl is swinging while sitting on a swing. When the girl stands up, the time period of the oscillations is-

Awill decrease
Bwill be more
Cwill depend on the height of the girl
Dwill remain unchanged

Question 16 of 50

Surface tension when soap is dissolved in water

Ahappens to
BIt increases.
Cremains unchanged
DFirst it decreases and then it increases.

Question 17 of 50

Archimedes' law is related to which of the following?

Alaw of flotation
BRight-angled triangle rule
Claw of gravity
Drelation between current and voltage

Question 18 of 50

If the diameter of the capillary tube is doubled, the height of the water rising in it will increase.

AIt doubles.
Bhalf remains
Cremains the same
Dbecomes zero

Question 19 of 50

small drop of oil spreads on water because

AThe viscosity of the oil is high
Bwater has high viscosity
COil has high surface tension
Dwater has high surface tension

Question 20 of 50

Assertion (A) Detergents easily remove oil and dirt from dirty clothes. Reason (R) Detergents increase the surface tension of water.

ABoth A and R are correct and R is the correct explanation of A.
BBoth A and R are correct, but R is not the correct explanation of A
CA is correct, but R is incorrect
DA is wrong, but R is correct

Question 21 of 50

The SI unit of momentum is

AAmpere
Bkgm/sec
CJoule
Dkgm

Question 22 of 50

body weight-

AIt is the same everywhere on the Earth's surface.
BIt is maximum at the poles.
Cis maximum at the equator
DIt is more prevalent on hills than on plains

Question 23 of 50

According to Newton's third law of motion and the force associated with the reaction-

Ashould always be focused on the same object
BCan be mounted on different objects
Cshould always be applied to different objects
DThe magnitudes of these do not have to be equal, but they must have the same direction.

Question 24 of 50

Why does a swimmer find it easier to swim in sea water than in river water?

AReduces pollution in sea water
BSea waves help a swimmer to float
CSea water has a higher density than ordinary water.
DThe ocean has a larger volume of water

Question 25 of 50

A runner runs for some distance before taking a long jump because-

ARunning makes jumping easier
BThis warms his body.
CThe inertia of his body while jumping helps him cover a greater distance.
DHe doesn't slip when he jumps

Question 26 of 50

Often, light thatched or tin roofs are blown away during a strong storm because-

ARoofs have complex shapes
BRoofs are not tightly fastened
CHigh velocity air flowing over the roof creates pressure on the roof surface and the pressure below the roof remains normal.
DThatched roofs blow away by strong winds

Question 27 of 50

What is the dimension of Planck's constant?

Aenergy
BLinear motion
Cangular velocity
DForce

Question 28 of 50

The time period of a geostationary satellite is-

A9 hours
B12 hours
C24 hours
D28 hours

Question 29 of 50

The principle of cleaning surfaces with soap is based on-

Aon viscosity
Bon flotation
Con elasticity
Don surface tension

Question 30 of 50

Match List-1 and List-II and select the correct answer from the codes given below: List-1 (Quantity) List-II (Unit) A. Electric force 1. Volt B. Electric charge 2. Newton C. Electric potential 3. Coulomb D. Electric capacitance 4. Farad

AABCD 1 2 3 4
BABCD 2 3 1 4
CABCD 4 3 2 1
DABCD 2 3 4 1

Question 31 of 50

A steel bullet floats in mercury because-

ANothing can sink in mercury.
BMercury has a higher density than steel.
CThe density of steel is greater than that of mercury.
DThe bullet cannot float

Question 32 of 50

The escape velocity of the Earth is-

A15 km/s
B21.1 km/s
C7.0 km/s
D11.2 km/s

Question 33 of 50

Automatic wristwatches are powered by

Afrom cramps
Bfrom the battery
Cfrom liquid crystals
DBy the various movements of our hands

Question 34 of 50

There is a difference between the mass and weight of a body because-

AMass is variable while weight is constant
BMass remains constant, while weight varies
Cboth are true
Dboth are wrong

Question 35 of 50

The bristles of a shaving brush stick together when removed from water. This is because:

ASurface tension
Bviscosity
Celasticity
Dfriction

Question 36 of 50

Skating on ice demonstrates that the melting point of ice increases with increasing pressure.

Aincreases
Bhappens to
Cremains unchanged
Dfirst decreases then increases

Question 37 of 50

Why can a person jump higher on the surface of the Moon than on the surface of the Earth?

AThe surface of the Moon is rough
Bthe moon has no atmosphere
CThe acceleration due to gravity on the Moon is less than on the Earth.
DThe moon is colder than the earth.

Question 38 of 50

The absorption of ink by blotting paper involves-

Aink viscosity
Bcapillary reaction phenomenon
Cdiffusion of ink through blotting
DSiphon action

Question 39 of 50

Energy is produced in the Sun by-

Aby nuclear fission
Bby nuclear fusion
Cby oxidation reactions
Dby reduction reactions

Question 40 of 50

Newton meter is the unit of-

Aof acceleration
Bof force
Cof power
Dof energy

Question 41 of 50

Time Period of the Pendulum

Adepends on the mass
Bdepends on the length
Cdepends on the temperature
Ddepends on the time

Question 42 of 50

When milk is churned vigorously, why does the cream separate from it?

AWhen milk is churned vigorously, why does the cream separate from it?
BThe centrifugal force is less than the weight of the water.
CThe weight of water at the highest position of the bucket is reduced by
DThe cohesive force between the water and the bucket is greater

Question 43 of 50

When is the apparent weight of a person in a lift less than his actual weight?

AWhen the elevator is going down rapidly
BWhen the lift is coming down at the same speed
CWhen the lift is moving up at a constant speed
Dwhen the elevator is going up fast

Question 44 of 50

A tennis ball bounces higher on a hill than on a plain because-

AThe air pressure is relatively low in the mountains.
BThe ball becomes lighter on the mountains
CThe acceleration due to gravity of the Earth decreases in the mountains.
Dnone of the above

Question 45 of 50

If the linear momentum of a moving body is doubled by the application of a force, then its kinetic energy-

Awill increase eightfold
Bwill increase fourfold
Cwill double
Dwill remain the same

Question 46 of 50

Which of the following statements is correct for a simple harmonic oscillator?

AThe acting force is directly proportional to the displacement from the mean position and is in the same direction
BThe acting force is directly proportional to the displacement from the mean position and is in the opposite direction.
CThe acceleration of the pendulum is constant
DThe velocity of the oscillator is not periodic

Question 47 of 50

Match List-I with List-II and select the correct answer using the code given below the lists. List-I List-II A High velocity 1. Mach B Wavelength 2. Angstrom C Pressure 3. Pascal D Energy 4. Joule

AABCD 2 1 3 4
BABCD 1 2 4 3
CB C D 1 2 3 4
DB C D 2 1 4 3

Question 48 of 50

Why do clouds float in the atmosphere?

Alow pressure
Blow density
Clow viscosity
Dlow temperature

Question 49 of 50

The SI unit of power 'Watt' is equivalent to what?

Akg m s 2
Bkg m 2 to 2
Ckg m2 to 3
Dnone of these

Question 50 of 50

Why are railway tracks banked on their banks?

AThe horizontal component of the train's weight can be used to obtain the required centrifugal force.
BNo frictional force can be generated between the wheels of the train and the tracks.
CThe horizontal component of the train's weight can be used to obtain the required centripetal force.
DThe train could not fall inwards